Apparatus for forming wheel rims

ABSTRACT

A process and apparatus for forming a drop center wheel rim wherein a substantially rectangular piece of metal is shaped into a cylindrical blank and the central portion thereof is engaged and progressively urged inwardly by pressure applying medium to form the drop center or well of the wheel rim. The partially formed wheel rim is then subjected to the action of first-stage male and female dies to further form the wheel rim and is then subjected to the action of male and female finishing dies to completely form the wheel rim. The process and apparatus permits wheel rims to be formed while minimizing, if not elimination, any tendency of the cylindrical blank to thin at areas known to be subjected to stress. The process and apparatus also permits the formation of wheel rims with reduced requirements as to space and time.

United States Patent [72] Inventor Earl T. Nukes Armstrong, Iowa 50514[21] Appl. No. 744,216 [22] Filed July 11, 1968 [45] Patented Apr. 13,1971 [54] APPARATUS FOR-FORMING WHEEL RIMS 9 Claims, 11 Drawing Figs.

[52] US. Cl 72/354, 72/402, 29/] 59.1 [51] Int. Cl B21d 22/00 [50] FieldofSearch 29/l59.1; 27/159; 72/353, 355, 357, 354, 402

[56] References Cited UNITED STATES PATENTS 2,291,393 7/1942 LeJeune29/159.1 2,586,029 2/ 1952 Greenshields et a1. 29/ 159. 1X 3,298,2181/1967 Gollwitzer 72/355 3,364,550 1/1968 Jessee et al. 29/159.1

illei FOREIGN PATENTS 130,413 12/1948 Australia 29/l 59.1 632,325 1H1949 Great Britain 29/1 59.1

Primary ExaminerJohn F. Campbell Assistant Examiner-Victor A. DiPalmaAtt0rney-Williamson, Palmatier & Bains ABSTRACT: A process and apparatusfor forming a drop center wheel rim wherein a substantially rectangularpiece of metal is shaped into a cylindrical blank and the centralportion thereof is engaged and progressively urged inwardly by pressureapplying medium to form the drop center or well of the wheel rim. Thepartially formed wheel rim is then subjected to the action offirst-stage male and female dies to further form the wheel rim and isthen subjected to the action of male and female finishing dies tocompletely form the wheel rim. The process and apparatus permits wheelrims to be formed while minimizing, if not elimination, any tendency ofthe cylindrical blank to thin at areas known to be subjected to stress.The process and apparatus also permits the formation of wheel rims withreduced requirements as to space and time.

Paulina April 13, 19.71 v 3,575,035

5 Sheets-Sheet 1 10 C81: ,9 MATERIAL- 2' l f $4222 EDGER DIE I E E I DROLL I l lflfinlig w i! m, 17

l I W .....A WM JUL 4 i I j l FINISHING I i M I ll DROP CENTER INVENTOR.424 I A/OK'S 4 7' mean s Patentd A ril 13', 1971 3,575,035

5 Sheets-Sheet2 I N VEN TOR. 421. Z Ala/a5 pmta 'April 13, 1971 5Sheets-Sheet 5 I N VENTOR 124 2' M04155 Paten t d April 13, 1911 5Sheets-Sheet 4 INVENTOR. 5484 I A/aegs' L g g 1 SUMMARY OF THE INVENTIONHeretofore, most wheel rims have been produced primarily in a rollingoperation in which the metallic blanks are shaped. Experience hasindicated that the production of conventional drop center wheel rimssometimes results in thinning of the material during the shapingoperation. It is, of course, desirable to produce wheel rims that are ofuniform thickness and that do not have deficient thickness dimensions atareas sub jected to stress. Conventional wheel forming installationrequires substantial space and therefore requires a substantial amountof time to completely fonn a wheel rim from a blank of material.

It is therefore an object of this invention to provide a process andapparatus for producing a wheel rim which is formed in a manner tominimize the occurrence of thinning of material during the shapingsteps. The apparatus system used in carrying out the process, requiressubstantially less space than that of conventional systems and requiressubstantially less time to completely finish a wheel rim than theconventional rolling system.

BRIEF DESCRIPTION OF THE FIGS. OF THE DRAWING FIG. I is a diagrammaticillustration of an apparatus system used in carrying out the steps ofthe process,

FIG. 2 is a top plan view of the drop center forming device with certainparts that are broken away from clarity,

FIG. 3 is a fragmentary perspective view of a portion of the drop centerforming device with a cylindrical blank positioned prior to entry intothe device,

FIG. 4 is a fragmentary perspective view of a portion of the drop centerforming device,

FIG. 5 is a diagrammatic perspective view illustrating the male andfemale die members of the first-stage die device,

FIG. 6 is a fragmentary cross-sectional view of the firststage diedevice fragmentarily illustrating portions of the male and female dieelements in a partially closed position and engaging a partially formedwheel rim,

FIG. 7 is a fragmentary cross-sectional view of the firststage diedevice similar to FIG. 6, but illustrating the male and female dieelements in the fully closed condition,

FIG. 8 is a fragmentary cross-sectional view of the secondstage diedevice with the die elements thereof in a partially closed conditionengaging the partially formed wheel rim,

FIG. 9 is a fragmentary cross-sectional view similar to FIG. b butillustrating the second-stage die elements in the fully closed positionto completely form the wheel rim,

FIG. 10 is a cross-sectional view of a modified form of the second-stagedie elements similar to FIG. 9 but illustrating a modification thereof,and

FIG. 11 is a perspective view similar to FIG. 4 illustrating a modifiedform of the drop-center forming device.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings andmore specifically to FIG. ll, it will be seen that the apparatus system,designated generally by the reference numeral 10, for carrying out theprocess is thereshown. The present process and apparatus systemcontemplates the continuous production of wheel rims which are generallyknown in the trade as drop center wheel rims. Such wheel rims areadapted for use on agricultural vehicles as well as other kinds ofvehicles.

In the present process, wheel rims are formed from metallic blanks. Ithas been found that thinning of material has been held to a minimum dueto forming process versus rolling process. The entire apparatus systemutilized in carrying out the process is relatively compact compared tothe conventional rolling system and the production of a wheel rim maytherefore be carried out in a relatively short time as compared to theconventional rolling system.

In the present process and apparatus system, as illustrated in FIG. 1,the metallic blanks from which the wheel rims are formed are unwoundfrom a coil of sheet steel 11, which may be supported in close proximityto an edger and feed roll device I2. The edger and feed roll device hassuitable rolls therein which engage the longitudinal edges of the stripof metallic material to shape the same into relatively smooth contour.This edging step is desirable, especially when the edges of the strip ofthe material have not been finished and have burrs and other roughenedsurface areas. The rolls of the edger device also function as feed rollsto convey the strip to a shear device where the strip of material is cutinto a rectangular blank I3 of predetermined size. In this regard, thesize of the blank will be determined by the size of the wheel rim to beformed. The width of the blank 13 will correspond generally to the axialdimension of the wheel rim while the length of the blank will correspondgenerally to the largest circumferential dimension of the wheel rim.

The rectangular blank B is thereafter conveyed to a coiler and weldingjig I4 when the rectangular blank B is coiled into cylindricalconfiguration and the abutting ends thereof are welded together to formthe cylindrical blank C. It is pointed out that the cylindrical blank Chas an axial dimension only slighter greater than the axial dimension ofthe finished wheel rim and the longitudinal dimension of the cylindercorresponds generally to the diameter of the large diametrical portionof the wheel rim.

The cylindrical blank C is then conveyed to a drop-center forming device15 where the central portion of the cylindrical blank C is deflecteduniformly inwardly to form the drop center of the finished wheel rim.Thereafter, the partially formed wheel is then directed to thefirst-stage die device 16 where the partially formed wheel rim isfurther shaped into partially finished condition and is finally directedto a finishing die device 17 wherein the partially formed wheel rim iscompletely formed. The partially formed wheel rim which results from theshaping step by the drop-center forming device is designated by thereference character D while the partially formed wheel rim produced bythe first-stage die device is designated by the reference character E.The finished wheel rim is designated by the reference character W.

Referring now to FIG. I and 9, it will be seen that the finished wheelrim W includes a cylindrical drop center portion 18 which constitutes asubstantial portion of the overall axial dimension of the wheel rim W.It will be noted, however, that the drop center portion 18 is offsetslightly axially although in other wheel rims, the drop center portionmay be centrally located. The drop center portion 18 is interconnectedto shoulders 19 by interconnecting portions 20. It will be noted thatthe interconnecting portions 20 flare outwardly from the drop centerportion, while the shoulders 19 are substantially cylindrical and aretherefore substantially coaxially disposed with respect to the dropcenter portion. Shoulders 19 are connected to flanges 20 which extendradially from the shoulders and terminate in beads 21 which in theembodiment shown in FIG. 9 are slightly rolled.

One of the most important features of the present invention is theformation of the drop center with respect to the cylindrical blank C. Itis pointed out above, the cylindrical blank C has a central portionthereof uniformly reduced in diameter in an unheated fonning step andreference is now made to FIGS. 2, 3 and I where the drop-center formingdevice I5 is thereshown.

The drop-center forming device 15 includes a housing 22 which isprovided with a centrally located opening 23 therein, the opening beingof. a size to accommodate the cylindrical blank C in loose fittingrelation therein. The drop-center forming device is provided with acylindrical segmented die 2.4 which defines the cylindrical opening 23interiorly of the housing 22. The cylindrical segmented die 24 iscomprised of a plurality of identical surface die elements 25 which areof substantially parallelogram configuration. It will be noted thatthesesurface die elements 25 are oriented so that the longitudinal edge26 of one die element is positioned'inproxirnal relation with aIongitudinal edge of an adjacent element. It will be noted that theselongitudinal edges are obliquely arranged. Each die element 26 alsoincludes an upper edge 27 and a lower edge 28.

The segmented die 24 also includes a plurality of similar liner dieelements 29 of parallelogram configuration and identical in constructionto the surface die elements 25. lt will be noted that the liner dieelements are obliquely oriented but oppositely oriented from the surfacedie elements and each includes longitudinal edges 30, an upper edge 31,and a lower edge 32.

A plurality of support members 33 are provided, each including avertically oriented plate 34 having a boss or sleeve 35 having anopening 36 therein. Each plate 34 has a mounting block 37 integrallyformed with the inner end thereof. Each surface die element 25 and itsassociated liner die element 29 is pivotally connected to one of themounting blocks 37 by pivot.

ln the embodiment shown, the surface die elements and liner die elementsare pivotally connected to every other mounting block 37. Each mountingblock 37 has an inwardly projecting upper lip 39 integrally formedtherewith and an inwardly projecting lower lip 40 integrally formedtherewith. The lower surface of the upper lip defines a camming surface41 and the upper surface of the lower lip 40 defines a camming surface42. The camming surface 41 engages the upper edges of the surface andliner die elements while the lower camming surface 42 is engageable withthe lower edges of the surface and liner die elements.

The sleeve 35 of each support member 33 is pivotally connected by pivotpin 43 to a link 44. Each link 44 is pivotally connected by pivot 45 toa lever 46 which is pivotally mounted on the housing by pivot pin 47.Elongate links 48 pivotally interconnect the outer end portions ofadjacent levers by pivot pins 49. It will be noted that each link 44 andeach lever 46 constitutes a toggle type linkage interconnecting eachsupport member 33. ms by shifting the toggle linkage, the supportmembers 33 are shifted radially inwardly and outwardly with respect tothe opening 23.

Suitable vertically oriented guide pins 50 are positioned on oppositesides of each plate 34 of each support member 33 to facilitate guidingof the plate in its inward and outward movement. A pair of verticallyoriented guide rollers 51 is positioned on the opposite sides of eachplate 34 to assist in guiding the support members in its movement.

Means are provided for operating the toggle linkage and this meansincludes a pair of double acting hydraulic piston and cylinder units 52,each comprising a cylinder having a piston axially movable therein whichis connected to a piston rod 54. Each hydraulic cylinder is pivotallymounted to a mounting plate 55 by means of a pivot 56, each plate 55being secured to the housing 22 and projecting outwardly therefrom.

The piston rod 54 of each hydraulic piston and cylinder unit ispivotally connected by means of a pivot 57 to one end of an elongatebell crank or lever 58. The lever 58 is pivotally connected by pivot 59to a mounting plate 60 which is also secured to the housing 22. Eachlever 58 has a plurality of links 61 pivotally secured thereto by pivots62 and these links 61 are also pivotally connected to certain of thelevers 46 by pivot 63. With this arrangement, extension and retractionof the hydraulic piston and cylinder units causes actuation of thetoggle linkage and thus inward and outward shifting movement of thesupport members 33.

it is pointed out that the cylindrical segmented die 24 is shiftablebetween an expanded retracted position and contracted inward position.When the segmented die 24 is in the expanded retracted position, asviewed in H0. 3, the support members will be retracted and the surfacedie elements will have their longitudinal edges spaced apart. The linerdie elements will also have their adjacent longitudinal edges spacedapart. However, as the toggle linkage is actuated to shift the supportmembers radially inwardly, the die elements will pivot about theirrespective pivot pins 38 by coaction with the camming surfaces of themounting blocks. Thus the segmented cylindrical die will engage thecentral portion of the cylindrical blank C and progressively deform thesame inwardly in a uniform fashion to form the drop center portion ofthe wheel rim. Although the cylindrical blank C will be in asubstantially unheated condition, the pressures created by the segmenteddie does generate some heat and a suitable coolant is supplied through aconduit 64 which is connected in communicating relation with a circulardischarge pipe 65 positioned above the segmented die to discharge aliquid coolant upon the die. lt will be noted that the pivotalconnections of the toggle linkage, actuating levers and piston andcylinder units are all vertically disposed so that the movements of theinterconnected parts are horizontally about vertical axes.

It will be seen that after the drop center portion of the wheel rim hasbeen formed, the end portions of the partially formed wheel rim are ofcylindrical configuration. This partially formed wheel rim is thenconveyed to the first-stage die device illustrated in H68. 5, 6 and 7.The first-stage die device includes a pair of male die members 66 whichare of similar configuration and a pair of female die members 67 also ofsimilar configuration with respect to each other. The female die membersare urged into embracing relation with respect to the exterior of thepartially formed wheel rim D. Then the male elements 66 are urged intoopposite ends of partially formed wheel rim D.

Means are provided for shifting the die members between open and closedpositions and to this end it will be seen that each male die member 66is secured to one end of an elongate ram 68. The outer end of each ram68 is pivotally connected to an arm 69 by pivot 70. The other end ofeach arm 69 is pivotally connected by pivot 71 to an arm structure 72which is secured to a revolvable vertical post 73. It will therefore beseen that by revolving the posts 73 about their vertical longitudinalaxes, the rams 68 will be extended and retracted to thereby move themale die members toward and away from each other.

The means for revolving each post 73 comprises a pair of double actinghydraulic piston and cylinder units 74 each including a cylinder 75having a piston movable therein to which is connected a piston rod 76.The piston rods 76 are connected to arms 77 which are secured to theassociated post 73. An elongate drag link 78 is pivotally connected atits ends to arms 79 carried by the posts 73. The drag link aids in theuniform action of the male die element during retraction and extensionthereof between open and closed positions.

The female die members 67 are also each connected to one end of anelongate ram 80, the other end of the ram 80 being pivotally connectedto an arm 81 by a pivot 82. The arm 81 is pivotally connected by a pivot83 to an arm 84 which is rigidly affixed to a revolvable vertical post85. The posts 85 are each revolved by hydraulic piston and cylinder unit86 comprised of a hydraulic cylinder 87 having a piston rod 88 securedto the piston thereof. The piston rod is secured to an arm 89 which issecured to the post 85. A drag link 90 is also pivotally connected ateach end to an arm 91 secured to the post 85. It will therefore be seenby extending and retracting the piston rod of each piston and cylinderunit, the posts 85 will be revolved and will shift the rams 80 towardand away from each other.

Means are also provided for releasably locking the female die members intheir closed position. Each female die member is provided with a lockingmechanism 92 although only one such locking mechanism is illustrated inFIG. 5. It is understood that a locking mechanism will be provided forthe other female die member. The locking mechanism 92 for each femaledie member comprises a locking bar 93 which is pivotally mounted bypivot 94 to the support structure which supports the first-stage diedevice. The locking bar 93 is therefore mounted for horizontal swingingmovement about a substantially vertical axis. A coil spring 95 bearsagainst the locking bar 93 and against a bearing member 96 which issecured to the supporting structure for the first-stage die device. Thusthe locking bar 93 is constantly urged inwardly.

against the associated female die member.

The locking bar 93 also has an elongate cam member 97 secured theretoand projecting inwardly therefrom. When the female die members are inthe retracted position, the locking bar 93 wild urge against the sidesurface 67a of the female die member. As the female die member is movedinwardly, into the fully closed position, the end edge of the lockingbar will engage the rear surface 671; of the female die member to lockthe female die member against retracted movement.

Referring to the sequence of FIG. 5, the female members 67 close firstgrasping partially formed wheel rim D, also allowing locks 97 to close.Then male die members 66 advance to the closed position. They thenreturn releasing locks 97 to permit female members 67 to return to thestarting position. Male die members 66 are also retracted prior to thefemale die members and when the male die members are retracted, the maledie members urge the cam members in a direction to pivot the lockingbars 93 out of engaging relation with respect to the female die membersthus allowing retraction thereof.

It is pointed out that the finishing or second-stage die members areidentical to the first-stage die members but for the respective diefaces of the male and female die members. Therefore, the actuatingmechanism associated with the finishing die device is identical to thatof the first-stage die device and a detailed description thereof isthought to be unnecessary.

Referring again to FIGS. 5, 6 and 7, it will be seen that each die maleelement 66 has a die face 98 comprised of a flat surface 99 whichconfronts the corresponding face on the other male die member. The dieface 98 also includes the surface 100 which together with the other maledie member corresponds to the inner surface of the drop center portion.The die face 98 includes a die surface 101 which flares outwardly fromthe surface 100 and further includes surface 102 which also flaresoutwardly but is more axially disposed than surface 100. Surface 103 iscontinuous with die surface 102 but flares more radially than the diesurface 102. Die face 98 also includes surface 104 which is shoulderedas at 140 so that the ends of the partially formed wheel rim engagethereagainst.

It will be noted that each female die member 67 has a die face 105 whichcomprises substantially one-half of the exterior surface of thepartially finished wheel rim. Die face 105 includes a die surface 106which corresponds to the exterior surface of the drop center portion.Die surfaces 107 flare outwardly from the surface 106 and match withsurface 101 of die faces 98. Die surface 108 are continuous with diesurfaces 107 and flare outwardly therefrom and cooperate in matchingrelation with die surfaces 102 of the die faces 98. Die face 105 alsoincludes die surface 109 which mates with die surface 103 and terminatesin die surfaces 110 which are substantially cylindrical inconfiguration. It will be noted that the die surfaces 100 of the maledie members have slightly different axial dimensions since in theembodiment shown the drop center portion is axially offset.

Referring now to FIGS. 8 and 9, it will be seen that the finishing diedevice 17 includes male die members 111 and female die members 112. Aspointed out above the finishing die device is identical in constructionto the first-stage die device except for the die faces of the respectivemale and female die members. In this regard, it will be noted that themale die members 111 each include a die face 113 having confrontingcircular surfaces 114. Each die face 113 also includes a die surface 115which is of cylindrical configuration and .which is continuous with diesurface 116 that flares outwardly from the die surface 115. Die surface117 extends substantially axially from die surface 116 and is continuouswith a faces 123 and each terminates in a substantially radial surface125 which mates with the associated radial surface 118. Surface 125 iscontinuous with an arcuate surface 126 of concave configuration andterminates in cylindrical surfaces 127. It will be noted that thearcuate surface 119 which is of convex configuration does not exactlymate with the associated arcuate concave surface 26 so that a smallrecess 127 is defined. It is felt that this recess permits the formationof the arcuate bead of the wheel rim with these match metal dies. Itwill also be noted that the surfaces of the male die members are ofdifferent axial length to accommodate the axially offset drop centerportion of the wheel rim. It will be noted that the embodimentillustrated in FIG. 10 of the finishing die device is identical to thatillustrated in FIGS. 8 and 9 except that the arcuate surface 119aextends outwardly to the adjacent shoulder so there is no recess definedas in the embodiment. That arcuate surface 119a cooperates with thearcuate surface a so that a recess 126a is provided in the manner of theembodiment of the dies of FIGS. 8 and 9. However, the omission of therecess 120 allows the arcuate bead to project more radially from theflange with less of an outward convexity than the embodiment of FIG. 9.

Referring now to FIG. 11, it will be seen that a slightly modified formof the cylindrical segment and die is 1 thereshown. This modifiedcylindrical segmented die is designated generally by the referencenumeral 24a and is positioned interiorly of the housing 22 and inwardlyof the opening 23. This segmented die also includes a plurality ofsimilar surface die elements 25a each having an upper edge 27a and alower edge 28a. Each die element 25a has a plurality of generallyrectangular obliquely arranged projecting teeth 26a extending fromopposite edge surfaces thereof. These teeth mate with the recesses 26bdefined by the teeth of the adjacent die element.

The liner die elements 29a is also identical to those shown in theembodiment of FIGS. 2, 3 and 4. The surface and liner die elements arepivotally connected to their associated support members by pivot pins38a and expansion and retraction of the segmented die is identical tothat of the embodiments of FIGS. 2, 3 and 4, except that the teeth ofeach surface die element shifts into and out of snug fitting relationwith respect to the associated recesses 26b of the adjacent surface dieelements. This arrangement will permit the segmented cylindrical die tobe expanded and contracted in the manner of the embodiment of FIGS. 2, 3and 4.

Referring again to FIG. 7, it will be noted that the shoulders on themale die members 66 engage the axial ends of the partially formed wheelrim thus causing upsetting of the rim as the male die members move tothe completely closed position. This occurs before the female diemembers 67 are moved into mating relation with respect to the male diemembers. Thus by upsetting or deforming the partially formed wheel rimprior to completely shaping or fonning of the same (by the coaction ofthe male and female die members), thinning of the material of thepartially formed wheel rim is held to a minimum.

It is also felt that by upsetting the partially formed wheel rim priorto completely shaping the various portions thereof also improves thegrain of molecular crystalline structure thereof of the metal. It iswhen the male and female die members of FIG. 7 are in the completelyclosed condition, that the upset or deformed portions of the partiallyformed rim structure are then permanently formed or shaped into theconfiguration illustrated by FIG. 8 of the drawing. It has been foundthat if the rim structure is formed without upsetting thereof, thenthinning of the material sometimes occurs and this is undesirable.However, not only does the first-stage die device minimize thinning butis so arranged and constructed to improve the grain structure of themetal.

From the foregoing description, it will be seen that I have provided anovel process and apparatus system which permits the formation of thedrop center wheel rims without the necessity of heating. It has beenfound that in my process, that there is absolutely no thinning of thethickness dimension of the cylindrical blank when the blank is shaped toform the drop center portion of the wheel rim. It is pointed out above,by utilizing an unheated system, the grain crystalline structure of themetal is improved as compared to that of a rolling operation. Theapparatus system may be compactly arranged and the process may becontinuously and quickly carried out.

Thus it will be seen that l have provided a novel process and apparatussystem which is not only of simple and inexpensive construction, but onewhich functions in a more efficient manner than any heretofore knowncomparable system.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the various partswithout departing from the scope of my invention.

lclaim:

l. Apparatus system for continuously forming drop center wheel rims,comprising:

a drop-center forming device for receiving and supporting a cylindricalblank, and comprising a generally cylindrical segmented die mechanismshiftable between an expanded retracted position and an advancedcontracted position, said die mechanism including a plurality ofsubstantially identical die elements, a plurality of shiftable supportmembers supporting said die elements, adjacent die elements when in theexpanded retracted position having adjacent edges spaced from each otherwhereby said die elements are disposed out of engaging relation withrespect to the cylindrical blank, and when shifted to the advancedcontracted position adjacent edges of adjacent die ele ments engagingeach other whereby said die elements engage the central exteriorcircumferential portion only of the cylindrical blank to deform thecentral portion of the cylinder uniformly inwardly and to shape thecylinder into a partially formed wheel rim including a pair ofcylindrical end portions of substantially the same diameter, acylindrical reduced central portion of substantially uniform diameter,and intermediate tapered portions interconnecting the centralcylindrical portion with the end portions, the reduced central portioncorresponding to the drop center of the finished wheel rim, and meansfor shifting said support members between advanced and retractedpositions;

a first-stage die device engaging the inner and outer surfaces of thepartially formed wheel rim to deform each cylindrical end portion into ashoulder portion and a flange portion;

a finishing die device engaging the inner and outer surfaces of thepartially fonned wheel rim to deform each shoulder portion intosubstantially coaxial relation with respect to said drop center portion,and to deform each flange portion to extend substantially radially fromits associated shoulder portion.

2. The apparatus system as defined in claim 1 wherein said means forshifting said support members include a plurality of toggle linkageseach being connected to one of said support members, and piston andcylinder units connected with said toggle linkages for shifting thesupport members between expanded and retracted positions.

3. The apparatus system as defined in claim 1 wherein said die elementseach have a plurality of teeth formed along adjacent edges thereof, theteeth on one die element being shiftable into mating relation with theteeth on the adjacent die element when the die elements are in theadvanced contracted position.

4. The apparatus system as defined in claim 1 wherein said first-stagedie device and said finishing die device each includes a pair of similarmale die members each having a die face and each being inserted into thepartially formed wheel rim, and a pair of similar female die memberseach having a die face, the die face of said female die membersembracing the exterior surface of the partially formed wheel rim.

5. The apparatus system as defined in claim 1 and means for supgortingand movin a strip of metallic materialthrough a pre etermmed path 0travel, a cutting mechanism in the path of travel of the strip and beingoperable to cut the strip into a rectangular sheet of predeterminedsize, means for coiling the sheet into cylindrical configuration, andmeans for coiling the sheet into cylindrical configuration, and meansfor welding the abutting ends of the coil sheet together to form thesame into the cylindrical blank prior to positioning the same in saiddrop-center forming device.

6. In an apparatus system for continuously forming drop center wheelrims, comprising:

a drop-center forming device for receiving and supporting a cylindricalblank, and comprising a generally cylindrical segmented die mechanismshiftable between an expanded retracted position and an advancedcontracted position, said die mechanism including a plurality ofsubstantially identical die elements, a plurality of shiftable supportmembers supporting said die elements, adjacent die elements when in theexpanded retracted position having adjacent edges spaced from each otherwhereby said die elements are disposed out of engaging relation withrespect to the cylindrical blank, and when shifted to the advancedcontracted position adjacent edges of adjacent die elements engagingeach other whereby said die elements engage the central exteriorcircumferential portion only of the cylindrical blank to deform thecentral portion of the cylinder uniformly inwardly and to shape thecylinder into a partially formed wheel rim including a pair ofcylindrical end portions of substantially the same diameter, acylindrical reduced central portion of substantially uniform diameter,and intermediate tapered portions interconnecting the centralcylindrical portion with the end portions, the reduced central portioncorresponding to the drop center of the finished wheel rim, and meansfor shifting said support members between advanced and retractedpositions.

7. The apparatus system as defined in claim 6 wherein said means forshifting said support members include a plurality of toggle linkageseach being connected to one of said support members, and piston andcylinder units connected with said toggle linkages for shifting thesupport members between expanded and retracted positions.

8. The apparatus system as defined in claim 6 wherein said die elementseach have a plurality of teeth formed along adjacent edges thereof, theteeth on one die element being shiftable into mating relation with theteeth on the adjacent die element when the die elements are in theadvanced contracted position.

9. The apparatus system defined in claim 1 wherein said finishing diedevice includes a pair of male die members and a pair of female diemembers, each female die member having a die face provided with annulararcuate recess therein adjacent the marginal portion thereof coactingwith said male die members to form an annular arcuate roll back beadintegral with each shoulder portion of the wheel rim.

1. Apparatus system for continuously forming drop center wheel rims,comprising: a drop-center forming device for receiving and supporting acylindrical blank, and comprising a generAlly cylindrical segmented diemechanism shiftable between an expanded retracted position and anadvanced contracted position, said die mechanism including a pluralityof substantially identical die elements, a plurality of shiftablesupport members supporting said die elements, adjacent die elements whenin the expanded retracted position having adjacent edges spaced fromeach other whereby said die elements are disposed out of engagingrelation with respect to the cylindrical blank, and when shifted to theadvanced contracted position adjacent edges of adjacent die elementsengaging each other whereby said die elements engage the centralexterior circumferential portion only of the cylindrical blank to deformthe central portion of the cylinder uniformly inwardly and to shape thecylinder into a partially formed wheel rim including a pair ofcylindrical end portions of substantially the same diameter, acylindrical reduced central portion of substantially uniform diameter,and intermediate tapered portions interconnecting the centralcylindrical portion with the end portions, the reduced central portioncorresponding to the drop center of the finished wheel rim, and meansfor shifting said support members between advanced and retractedpositions; a first-stage die device engaging the inner and outersurfaces of the partially formed wheel rim to deform each cylindricalend portion into a shoulder portion and a flange portion; a finishingdie device engaging the inner and outer surfaces of the partially formedwheel rim to deform each shoulder portion into substantially coaxialrelation with respect to said drop center portion, and to deform eachflange portion to extend substantially radially from its associatedshoulder portion.
 2. The apparatus system as defined in claim 1 whereinsaid means for shifting said support members include a plurality oftoggle linkages each being connected to one of said support members, andpiston and cylinder units connected with said toggle linkages forshifting the support members between expanded and retracted positions.3. The apparatus system as defined in claim 1 wherein said die elementseach have a plurality of teeth formed along adjacent edges thereof, theteeth on one die element being shiftable into mating relation with theteeth on the adjacent die element when the die elements are in theadvanced contracted position.
 4. The apparatus system as defined inclaim 1 wherein said first-stage die device and said finishing diedevice each includes a pair of similar male die members each having adie face and each being inserted into the partially formed wheel rim,and a pair of similar female die members each having a die face, the dieface of said female die members embracing the exterior surface of thepartially formed wheel rim.
 5. The apparatus system as defined in claim1 and means for supporting and moving a strip of metallic materialthrough a predetermined path of travel, a cutting mechanism in the pathof travel of the strip and being operable to cut the strip into arectangular sheet of predetermined size, means for coiling the sheetinto cylindrical configuration, and means for coiling the sheet intocylindrical configuration, and means for welding the abutting ends ofthe coil sheet together to form the same into the cylindrical blankprior to positioning the same in said drop-center forming device.
 6. Inan apparatus system for continuously forming drop center wheel rims,comprising: a drop-center forming device for receiving and supporting acylindrical blank, and comprising a generally cylindrical segmented diemechanism shiftable between an expanded retracted position and anadvanced contracted position, said die mechanism including a pluralityof substantially identical die elements, a plurality of shiftablesupport members supporting said die elements, adjacent die elements whenin the expanded retracted position having adjacent edges spaced fromeach other whereby said die elements ARE disposed out of engagingrelation with respect to the cylindrical blank, and when shifted to theadvanced contracted position adjacent edges of adjacent die elementsengaging each other whereby said die elements engage the centralexterior circumferential portion only of the cylindrical blank to deformthe central portion of the cylinder uniformly inwardly and to shape thecylinder into a partially formed wheel rim including a pair ofcylindrical end portions of substantially the same diameter, acylindrical reduced central portion of substantially uniform diameter,and intermediate tapered portions interconnecting the centralcylindrical portion with the end portions, the reduced central portioncorresponding to the drop center of the finished wheel rim, and meansfor shifting said support members between advanced and retractedpositions.
 7. The apparatus system as defined in claim 6 wherein saidmeans for shifting said support members include a plurality of togglelinkages each being connected to one of said support members, and pistonand cylinder units connected with said toggle linkages for shifting thesupport members between expanded and retracted positions.
 8. Theapparatus system as defined in claim 6 wherein said die elements eachhave a plurality of teeth formed along adjacent edges thereof, the teethon one die element being shiftable into mating relation with the teethon the adjacent die element when the die elements are in the advancedcontracted position.
 9. The apparatus system defined in claim 1 whereinsaid finishing die device includes a pair of male die members and a pairof female die members, each female die member having a die face providedwith annular arcuate recess therein adjacent the marginal portionthereof coacting with said male die members to form an annular arcuateroll back bead integral with each shoulder portion of the wheel rim.